70-Meter Long Acrylic Fiber Pre-Oxidation Tunnel Furnace

The 70-meter long acrylic fiber pre-oxidation tunnel furnace is a core thermal processing equipment in carbon fiber production lines. It is mainly used for the staged thermal stabilization (pre-oxidation) treatment of polyacrylonitrile (PAN) precursor fibers.

Product Applications

Pre-Oxidation of Precursor Fibers:

Used for continuous stretching and thermal treatment of PAN precursor fibers in an air atmosphere at 200℃–300℃.

Molecular Chain Cross-Linking:

Promotes the transformation of linear polymer chains into heat-resistant ladder-type six-membered ring structures.

Prevention of Melting and Carbonization:

Improves the thermal stability of fibers, ensuring that they do not melt or burn during the subsequent high-temperature carbonization process.

Product Parameters

Product Features

Ultra-Long Uniform Temperature Control:

The equipment adopts precision multi-zone independent temperature control to ensure highly uniform temperature distribution throughout the 70-meter furnace chamber.

Flexible Tension Control:

Equipped with high-precision traction roller systems to strictly control fiber shrinkage and stretching during the pre-oxidation process.

Efficient Exhaust Gas Removal:

The specially designed tar removal and exhaust gas system timely removes reaction by-products and prevents fiber contamination.

Energy-Saving Insulation Structure:

Uses a high-density composite refractory fiber insulation layer to significantly reduce heat loss from the furnace body surface.

FAQ

Q1: How does a 70-meter-long furnace ensure uniform temperature inside the chamber?

A1: The equipment adopts a segmented independent temperature control design. Each section is equipped with a high-precision hot air circulation system and air guide plates, ensuring that the local temperature difference is controlled within ±1℃.

Q2: How are toxic exhaust gases generated during the pre-oxidation process treated?

A2: The furnace body is equipped with multiple exhaust suction points to collect reaction-generated gases such as hydrogen cyanide and ammonia, which are then sent to catalytic combustion or regenerative thermal oxidizer (RTO) purification systems for treatment.

Q3: Why does the pre-oxidation tunnel furnace need to be as long as 70 meters?

A3: PAN precursor fiber pre-oxidation is a chemical exothermic reaction that must proceed slowly within a specific temperature range. A longer furnace body provides sufficient residence time for the fibers and improves production capacity.

Q4: How does the equipment prevent fiber breakage or entanglement inside the furnace?

A4: The system integrates tension sensors and variable frequency drives to adjust the speed of each roller section in real time. It is also equipped with automatic fiber breakage alarms and positioning systems.

Q5: What daily maintenance operations are required for this equipment?

A5: Regular maintenance includes cleaning accumulated tar deposits in circulating fans and air ducts, checking the resistance values of heating elements, and calibrating the thermocouples of each temperature zone.